Totally implantable enzymatic biofuel cell and brain stimulator operating in bird through wireless communication

Animals digest food to fuel brain neurometabolism via cellular respiration. This study demonstrates the combination of a biofuel cell (BFC) and an animal brain stimulator (ABS) implanted in a pigeon. Glucose oxidation and oxygen reduction in an enzymatic BFC supplied electrical power to the ABS. Power from the BFC reached 0.12 mW in vitro and 0.08 mW in vivo using only the natural glucose and oxygen in the pigeon's body. A power management integrated circuit is used to harvest energy from the in vivo BFC at a rate of 28.4 mJ over 10 min, which is sufficient for intermittent neurostimulation.

Sheet Resistance Analysis of Interface-Engineered Multilayer Graphene: Mobility Versus Sheet Carrier Concentration

Both interlayer-undoped and interlayer-doped multilayer graphenes were prepared by the multiple transfers of graphene layers with multiple Cu etching (either dopant-free or doped during etching) and transfer, and the effect of interface properties on the electrical properties of multilayer graphene was investigated by varying the number of layers from 1 to 12. In both the cases, the sheet resistance decreased with increasing number of layers from 700 to 104 Ω/sq for the interlayer-undoped graphene and from 280 to 25 Ω/sq for the interlayer-doped graphene. Further, Hall measurements revealed that the origins of the sheet resistance reduction in the two cases are different. In the interlayer-undoped graphene, the sheet resistance decreased because of the increase in mobility with the addition of inner layers, which has a low carrier density and a high carrier mobility. On the other hand, it decreased because of the increase in sheet carrier density in the interlayer-doped multilayer graphene. The mobility and carrier density variations in both the cases were confirmed by fitting with the model of Hall effect in the heterojunction. In addition, we found that surface property modification by the doping of the top layer and the formation of double-layer graphene with different partial coverages allow the separate control of carrier density and mobility. Our study provides an effective approach for controlling the properties of multilayer graphene for electronic applications.

Transparent Conductive Electrodes of β-Ga₂O₃/Ag/β-Ga₂O₃ Multilayer for Ultraviolet Emitters

We investigated the optical and electrical properties of a β-Ga₂O₃/Ag/β-Ga₂O₃ multilayer transparent conductive electrode deposited on an α-Al2O₃ (0001) substrate. For the deposition of a continuous Ag layer, we preliminarily performed anultraviolet-ozone pretreatment of the Ga₂O₃ bottom layer. To obtain a stable β-phase of Ga₂O₃, the β-Ga₂O₃/Ag/β-Ga₂O₃ multilayer was annealed at 700 °C under N₂ atmosphere. The transmittance and sheet resistance of the β-Ga₂O₃/Ag/β-Ga₂O₃ multilayer were critically affected by the surface morphology and thickness of the Ag interlayer. The multilayer with optimized thicknesses (β-Ga₂O₃ top layer: 30 nm; Ag interlayer: 12 nm; β-Ga₂O₃ bottom layer: 60 nm) exhibited a resistance of 8.48 Ωsq^-1, an average optical transmittance of 87.16% in the ultraviolet wavelength range from 300 to 350 nm, and a figure of merit of 29.81 × 10^-3 Ω^-1.

The roughening kinetics of hydrogenated graphene

The roughness is a common property of all growing surfaces – however, the way the roughness of a growing surface changes with time and space is uniquely related to the underlying growth process, i.e. to how the atoms stick to the surface during the first stage of nucleation. This concept allows getting insights on the nucleation process of a growing surface by measuring two scaling exponents, α and β, known as roughness and growth exponents, respectively. In this work, we studied hydrogenation of graphene using the roughening kinetics. The coverage of graphene will depend on how the H ions stick on the surface, giving rise to a unique roughness evolution in time and space. We measured a roughness exponent of ~0.5 (derived from a Fourier index of ~3), and a growth exponent of ~0.3. The values of the growth and roughness exponents are close to those reported for clustered carbon, suggesting a roughening mechanism by clustering, in good agreement with the theory. We also compared our coverage data with a different model, used to describe the dynamics of graphene coverage, during chemical vapour deposition. Our data are in agreement with a nucleation-dominated growth, further confirming that hydrogenation is happening by clustering.

Prospective multinational serosurveillance study of Bordetella pertussis infection among 10- to 18-year-old Asian children and adolescents

OBJECTIVES

Bordetella pertussis continues to cause outbreaks worldwide. To assess the role of children and adolescent in transmission of pertussis in Asia, we performed a multinational serosurveillance study.

METHODS

From July 2013 to June 2016, individuals aged 10 to 18 years who had not received any pertussis-containing vaccine within the prior year were recruited in 10 centres in Asia. Serum anti-pertussis toxin (PT) IgG was measured by ELISA. Demographic data and medical histories were obtained. In the absence of pertussis immunization, anti-PT IgG ≥62.5 IU/mL was interpreted as B. pertussis infection within 12 months prior, among them levels ≥125 IU/mL were further identified as infection within 6 months.

RESULTS

A total of 1802 individuals were enrolled. Anti-PT IgG geometric mean concentration was 4.5, and 87 (4.8%) individuals had levels ≥62.5 IU/mL; among them, 73 (83.9%) had received three or more doses of pertussis vaccine before age 6 years. Of 30 participants with persistent cough during the past 6 months, one (3.3%) had level ≥125 IU/mL. There was no significant difference in proportions with anti-PT IgG ≥62.5 IU/mL among age groups (13-15 vs. 10-12 years, 16-18 vs. 10-12 years), between types of diphtheria, pertussis and tetanus (DTP; whole cell vs. acellular), number of doses before age 6 years within the DTP whole-cell pertussis vaccine (five vs. four doses) or acellular pertussis vaccine (five vs. four doses) and history of persistent cough during the past 6 months (yes vs. no).

CONCLUSIONS

There is significant circulation of B. pertussis amongst Asian children and adolescents, with one in 20 having serologic evidence of recent infection regardless of vaccination background.

Impact of Early Hospital Readmissions After Kidney Transplantation on Graft Function

Early hospital readmissions are common after kidney transplantation. This single-center retrospective study investigated the relationship between early hospital readmissions and clinical outcomes. All adult patients receiving a kidney transplant at this center between March 2009 and June 2015 were included. The early hospital readmissions within the first 30 days were numbered, and the diagnosis was ascertained. The patients were divided into None and Readmission groups. Clinical outcomes and patient- and death-censored graft survival were compared. Among the 103 patients included in the study, 32 (31.1%) had 1 or more readmissions within 30 days. Surgical complications, electrolyte imbalance, and acute rejection were common causes of readmission. No differences were observed in baseline characteristics between the two groups. Patients with early readmissions exhibited low renal function at 3, 6, and 12 months postoperatively (P = .002, .020, and .013, respectively). No difference in graft function was found 12 months after transplantation between the None and Readmission groups. Five-year graft and patient survival also showed no difference between the two groups (P = .424 and .442, respectively). In conclusion, early readmission after kidney transplantation affected lower graft function until 1 year after kidney transplantation. However, the long-term effect on graft function is limited in this study.

Early Weight Gain After Transplantation Can Cause Adverse Effect on Transplant Kidney Function

BACKGROUND

The outcomes of kidney transplant recipients with increased body mass index (BMI) remain controversial. We studied the relationship between changes in BMI and kidney transplant function, especially during the first year after transplantation.

METHODS

We performed an observational cohort study of all kidney transplant recipients at our center from March 2009 to June 2014 to determine whether changes in BMI were associated with kidney transplant function, as measured by estimated glomerular filtration rate (eGFR). Recipient BMI and eGFR were calculated pre-transplant and at 1, 3, 6, 9, and 12 postoperative months (POM) after transplantation. The correlation between changes in BMI and eGFR was then evaluated.

RESULTS

Eighty-one patients were studied. There was a strong negative correlation between changes in BMI and eGFR from pre-transplant to POM 1 (correlation coefficient, -0.406; P < .0001) and from POM 1 to POM 3 (r = -0.324, P = .004).

CONCLUSIONS

We found that increased BMI caused a significant decline in renal function as measured by eGFR, especially in the initial 3 months after kidney transplantation.

Adjustment Experience of Kidney Transplantation Recipients in Korea

BACKGROUND

The purpose of this study was to understand the adjustment process after kidney transplantation.

METHODS

The research method followed grounded theory methodology of Strauss and Corbin. Twelve recipients after kidney transplantation were selected. The data were collected through in-depth, face-to-face interviews or e-mailing or phone-interviews and analyzed by means of a constant comparative method.

RESULTS

Through the category analysis, "struggling for independence" was verified as the central phenomenon of recipients, and the causal conditions that influence this phenomenon were "unpredictable physical status," "the difficulty of self-care," "apathy of families and friends," and "emotional instability." The contextual conditions were "social prejudice" and "difficulty in returning to society," and the intervening conditions were "significant others support" and "religious support." The action/interaction strategies were "inner reviewing strategies," "interactive strategies," and "active self-maintaining strategies." From this observation, "establishing guidelines for living" was derived as the result.

CONCLUSIONS

The results of this study provided deep understanding on the adjustment process after kidney transplantation, and this would help to provide a frame for individualized medical and nursing intervention strategies in assisting the psychosocial adaptation of the kidney transplantation recipient.

Improved DFT Potential Energy Surfaces via Improved Densities

Density-corrected DFT is a method that cures several failures of self-consistent semilocal DFT calculations by using a more accurate density instead. A novel procedure employs the Hartree-Fock density to bonds that are more severely stretched than ever before. This substantially increases the range of accurate potential energy surfaces obtainable from semilocal DFT for many heteronuclear molecules. We show that this works for both neutral and charged molecules. We explain why and explore more difficult cases, for example, CH(+), where density-corrected DFT results are even better than sophisticated methods like CCSD. We give a simple criterion for when DC-DFT should be more accurate than self-consistent DFT that can be applied for most cases.

Indole derivatives inhibit hepatitis C virus replication through induction of pro-inflammatory cytokines

Previously, we discovered a series of indole derivatives as a new class of hepatitis C virus (HCV) replication inhibitors by using a target-free chemical genetic strategy. Through a structure-activity relationship study, the compound 12e was identified as the most potent inhibitor of this class (EC50 = 1.1 μmol/l) with minimal cytotoxicity (CC50 = 61.8 μmol/l). In order to gain insight into its detailed antiviral mechanism of action, we performed PCR array analyses and found that 12e was able to activate transcription of a number of pro-inflammatory as well as antiviral cytokine genes including CXCL-8, IL-1α, TNF-α, IL-3, IRAK-1, and DDX58. Their induction by 12e was verified by individual RT-PCR analyses. In addition, 12e was found to stimulate secretion of soluble factors with anti-HCV replication activity. Among the 12e-induced pro-inflammatory cytokines, CXCL-8 showed a strong positive correlation between its transcriptional activation and antiviral potency. Interestingly, a recombinant CXCL-8 protein also reduced HCV replication, though only moderately. In conclusion, we found a novel mode of action of indole derivatives in inhibiting HCV replication, particularly the induction of pro-inflammatory cytokines.

Active control of all-fibre graphene devices with electrical gating

Active manipulation of light in optical fibres has been extensively studied with great interest because of its compatibility with diverse fibre-optic systems. While graphene exhibits a strong electro-optic effect originating from its gapless Dirac-fermionic band structure, electric control of all-fibre graphene devices remains still highly challenging. Here we report electrically manipulable in-line graphene devices by integrating graphene-based field effect transistors on a side-polished fibre. Ion liquid used in the present work critically acts both as an efficient gating medium with wide electrochemical windows and transparent over-cladding facilitating light–matter interaction. Combined study of unique features in gate-variable electrical transport and optical transition at monolayer and randomly stacked multilayer graphene reveals that the device exhibits significant optical transmission change (>90%) with high efficiency-loss figure of merit. This subsequently modifies nonlinear saturable absorption characteristics of the device, enabling electrically tunable fibre laser at various operational regimes. The proposed device will open promising way for actively controlled optoelectronic and nonlinear photonic devices in all-fibre platform with greatly enhanced graphene–light interaction.

Active control of light in optical fibres is of great interest, to this end, electric control of all-fibre graphene devices is desirable but highly challenging. Here, Lee et al. demonstrate electric control of the optical properties of a graphene sheet deposited on a side-polished fibre mediated by an ion liquid.

Carbon monoxide and nitric oxide interactions in magnocellular neurosecretory neurones during water deprivation

Nitric oxide (NO) and carbon monoxide (CO) are diffusible gas messengers in the brain. Previously, we have shown their independent involvement in central fluid/electrolyte homeostasis control. In the present study, we investigated a possible functional interaction between NO/CO in the regulation of vasopressin (VP) and oxytocin (OT) magnocellular neurosecretory cells (MNCs) activity in euhydrated (EU) and dehydrated [48-h water-deprived (48WD)] rats. Using brain slices from EU and 48WD rats, we measured, by immunohistochemistry, the expression of neuronal NO synthase (nNOS, which synthesises NO) and haeme-oxygenase (HO-1, which synthesises CO) in the hypothalamic supraoptic nucleus (SON). In addition, we used patch-clamp electrophysiology to investigate whether regulation of SON MNC firing activity by endogenous CO was dependent on NO bioavailability and GABAergic inhibitory synaptic function. We found a proportion of OT and VP SON MNCs in EU rats to co-express both of HO-1 and nNOS (33.2 ± 2.9% and 15.3 ± 1.4%, respectively), which was increased in 48WD rats (55.5 ± 0.9% and 21.0 ± 1.7%, respectively, P < 0.05 for both). Inhibition of endogenous HO activity [chromium mesoporphyrin IX chloride (CrMP) 20 μm] induced MNC membrane hyperpolarisation and decreased firing activity, and these effects were blunted by previous blockade of endogenous NOS activity (l-NAME, 2 mm) or blockade of inhibitory GABA function [Picrotoxin (Sigma-Aldrich, St Louis, MO, USA), 50 μm]. No significant changes in SON NO bioavailability (4,5 diaminofluorescein diacetate fluorescence) were observed after CrMP treatment. Taken together, our results support a state-dependent functional inter-relationship between NO and CO in MNCs, in which CO acts as an excitatory gas molecule, whose effects are largely dependent on interactions with the inhibitory SON signals NO and GABA.

Non-invasive assessment of cutaneous wound healing using fluorescent imaging

BACKGROUND/PURPOSE

Optical imaging is a very important technique in the biomedical sciences. The purpose of this study was to develop an in vivo optical system for fluorescent imaging and molecular imaging applications using quantum dots (QDs).

METHODS

The in vivo optical system was composed of modular parts, including a light source, light guide, excitation filter wheel, excitation filters, emission filter wheel, emission filters, liquid crystal tunable filter (LCTF), macro lens, dark chamber, and a cooled charged-coupled device (CCD) camera for recording images. Filters were selected based on the excitation and absorption spectra of QDs to allow spectral separation and optimization of the acquired image. In contrast with conventional systems, our system allows selection of the emission bandwidth.

RESULTS

The system was tested in an in vivo study using a wound-healing model in nude mice. The healing process was examined after injection of fibroblasts and keratinocytes labeled with two different sets of QDs. The different QD probes were readily detected and distinguished using our system.

CONCLUSION

An in vivo optical system is a very useful tool for the detection of genes, proteins, and small-molecule drugs inside living animals, and this imaging modality can also be adopted for real-time visualization of cancer cell metastasis in live animals.

Frequency downshift of Nd:YAG lasers and terahertz radiation

The interaction between an intense laser and a cotraveling relativistic dense electron beam could result in the downshifting of the laser frequency. It is theoretically analyzed that this process can generate a coherent terahertz radiation. The radiation energy could reach the order of 1 mJ per shot in the duration of 100 ps, or a temporal radiation power of 10 MW, with a set of practically relevant parameters.

Enhanced expression of heme oxygenase-1 and carbon monoxide excitatory effects in oxytocin and vasopressin neurones during water deprivation

A growing body of evidence indiates that carbon monoxide (CO) acts as a gas neurotransmitter within the central nervous system. Although CO has been shown to affect neurohypophyseal hormone release in response to osmotic stimuli, the precise sources, targets and mechanisms underlying the actions of CO within the magnocellular neurosecretory system remain largely unknown. In the present study, we combined immunohistochemistry and patch-clamp electrophysiology to study the cellular distribution of the CO-synthase enzyme heme oxygenase type 1 (HO-1), as well as the actions of CO on oxytocin (OT) and vasopressin (VP) magnocellular neurosecretory cells (MNCs), in euhydrated (EU) and 48-h water-deprived rats (48WD). Our results show the expression of HO-1 immunoreactivity both in OT and VP neurones, as well as in a small proportion of astrocytes, both in supraoptic (SON) and paraventricular (PVN) nuclei. HO-1 expression, and its colocalisation with OT and VP neurones within the SON and PVN, was significantly enhanced in 48WD rats. Inhibition of HO activity with chromium mesoporphyrin IX chloride (CrMP; 20 μm) resulted in a slight membrane hyperpolarisation in SON neurones from EU rats, without significantly affecting their firing activity. In 48WD rats, on the other hand, CrMP resulted in a more robust membrane hyperpolarisation, significantly decreasing neuronal firing discharge. Taken together, our results indicate that magnocellular SON and PVN neurones express HO-1, and that CO acts as an excitatory gas neurotransmitter in this system. Moreover, we found that the expression and actions of CO were enhanced in water-deprived rats, suggesting that the state-dependent up-regulation of the HO-1/CO signalling pathway contributes to enhance MNCs firing activity during an osmotic challenge.

Current-drive efficiency in a degenerate plasma

In a degenerate plasma, the rates of electron processes are much smaller than the classical model would predict, affecting the efficiencies of current generation by external noninductive means, such as by electromagnetic radiation or intense ion beams. For electron-based mechanisms, the current-drive efficiency is higher than the classical prediction by more than a factor of 6 in a degenerate hydrogen plasma, mainly because the electron-electron collisions do not quickly slow down fast electrons. Moreover, electrons much faster than thermal speeds are more readily excited without exciting thermal electrons. In ion-based mechanisms of current drive, the efficiency is likewise enhanced due to the degeneracy effects, since the electron stopping power on slow ion beams is significantly reduced.

[Prevalence of hepatitis A, B, C and E virus markers among patients with elevated levels of Alanine aminotransferase and Aspartate aminotransferase in Phnom Penh (Cambodia) and Nha Trang (Central Vietnam)]

In order to describe the respective part of viral hepatitis in liver diseases observed in Cambodia and Vietnam, ninety consecutive patients with Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) > or = 100 Ul/l were tested for hepatitis A, B, C and E markers in Phnom Penh and Nha Trang. The markers were IgM antibodies to hepatitis A virus (anti-HAV IgM), hepatitis B surface antigen (HBsAg), antibodies to hepatitis C virus (anti-HCVAb) and IgG antibodies to hepatitis E virus (anti-HEV IgG). Recruited patients were predominantly adults and male (sex ratio 76%). Among these patients, 81% were tested positive to at least one marker in Nha Trang and 79% in Phnom Penh. In Nha Trang, HBsAg was more frequent (73%) than anti-HCV Ab (9%) while in Phnom Penh both markers were closely similar (HBsAg: 41%, anti-HCV Ab: 39%). In both population samples, HBsAg was more prevalent among young people whereas anti-HCV Ab were only detected in adults. No case of acute HAV infection was diagnosed in Nha Trang while anti-HAV IgM were detected in 20% of Cambodian patients. Anti-HEV IgG were infrequent (2% in Nha Trang, 5.5% in Phnom Penh). Only one case was notified, a male Vietnamese patient probably suffering from acute hepatitis E. More studies would be useful to improve the control measures against viral hepatitis in the public health programs.

Caffeic acid phenethyl ester (CAPE): synthesis and X-ray crystallographic analysis

The structure of caffeic acid phenethyl ester [2-propenoic acid, 3-(3,4-dihydroxyphenyl)-, 2-phenethyl ester] (I), C17H16O4 x 1/2C6H6, synthesized by base-catalyzed alkylation of caffeic acid salt with beta-bromoethylbenzene in HMPA (hexamethylphosphoramide) and recrystallized from benzene, was confirmed by single crystal X-ray diffraction. The crystals are triclinic, space group P1, Z=2, unit cell dimension a=5.8129 (9) A, b=11.122 (2) A, c=13.226 (2) A, alpha=97.080 (3) degrees, beta=101.467 (3) degrees, gamma=95.405 (3) degrees , V=825.4 (2) A3, Dcalc=1.301 g/cm3, F(000)=342. The packing of the molecule is stabilized by intermolecular O1H...O4 (2.69 A) and O1...HO2 (2.82 A) hydrogen bonds.